Phonograph record disc

ABSTRACT

A synthetic resin moulded product has a moulded label equivalent portion. A mirror-like, smooth surface on the product has a predetermined pattern. A coarse surface on other parts are formed with a pattern having extremely minute and fine projections and depressions. The label equivalent portion indicates the predetermined pattern by a contrast of lusterless parts and lustrous parts. The manufacturing method produces the synthetic resin moulded product with the label equivalent portion.

States Patent 1 1 [111 3,787,27 Genma Jan, 22, 1974 [54] PHONOGRAPH RECORD DISC 1,178,257 4/1916 Haley 161/2 [751 Inventor Susumu Gem, Tokyo, Japan 5:133:33? 1111323 565211113: jjiiiiiiiiijia's'o'yl'fiZ Assignee: Victor Company of Jap Schaum Yokohama-city, Kanagawa-ken, Japan P E w'11' A P 11 rzmary xammer 1 1am owe [22] Flled: May 1971 Attorney, Agent, or FirmLouis Bernat [21] Appl. N0.: 145,688

[30] Foreign Application Priority Data May 25, 1970 Japan 45/44660 [57] ABSTRACT May 25, 1970 Japan 45/44659 A synthetic resin moulded product has a moulded [52] US. Cl 161/116, 156/14, 161/42, label equivalent p A mirror-like, smooth 161/ 1 19, 161/413 264/107 face on the product has a predetermined pattern. A 51 Int. (:1 'B32b 3/00 coarse surface on o h parts are formed'with a [58] Field Of Search 264/106, 107, 1, 220, 227, tern having extremely minute and fine Projections and 264/284,'293; 156/62, 209, 219, 220, 14, 3; depressions. The label equivalent portion indicates the 161/2, 1 16, 413, 1 19, 42, 4; 274/42, 43, 44, predetermined pattern by a contrast of lusterless parts 9 11 17 and lustrous parts. The manufacturing method produces the synthetic resin moulded product with the [56] I I R f e Ci d 1 label equivalent portion. 1

UNITED STATES PATENTS 1,347,668 7/1920 Aylsworth et a1 .1264 107 4 Claims, 20 Drawing Figures VIII/III! PATENTEUJANZEISM I 37,871,274

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Susumu GEN/V711) BY H'n'ToRNEv PATENTED Z saw a nr 6 INVENTOR u sumu GENMH V 4 40 4 4 HTTORNEY PATENTED 3,787, 274

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HTTORNEY PHONOGRAPII RECORD DISC This invention relates to synthetic resin moulded products and more particularly to a method of manufacturing the same. A synthetic resin moulded product is capable of indicating its contents without requiring the attaching of a label thereto. This is done by moulding the portion, which is equivalent to the label, integrally with the product proper in a moulding process.

By way of an example, of the synthetic resin moulded product, the description will be made hereinafter with reference to a record disc. A conventional record disc is press-moulded in the following process; First, labels for both the A-side and B-side are made of printed paper. Then, each label is mounted on a stamper or die with the reverse side out, guided by a center pin of a press machine. Nextly, a required quantity of preheated and kneaded vinyl material is injected between two stampers or dies. The two stampers or dies are pressed against together to heat, press, and cool the injected material, whereby a record disc ismanufactured. These labels are generally required to indicate the name of the music recorded on the record disc, the names of its composers, and its players etc. The labels adhere to the heated andmelted material, in the process of pressmoulding. They are stuck fast to the record disc when it has cooled off and taken out of the stampers or dies of the press.

However, the conventional method of manufacturing the record disc, using the labels of printed paper, has the following disadvantages; (l) The operation of mounting labels on the press machine is required. This is a great hindrance to making record discs, with a wasteful use of man power and'a lengthening of a record disc manufacturing cycle. (2) Printing, drying, delivery etc. of labels require many process steps, a great deal of time, and the cost of a record disc increases by the cost of the labels. (3) In the press-moulding of record discs, irregularity or breakage of labels frequently takes place. Also errors are committed by an operator in mounting labels on the press machine. These factors obstruct improvement of productivity in the record disc production. (4) In case a defective record disc is crushed and regenerated as new vinyl material, the labeled part is blanked or cut out and destroyed, and the rest of the record disc is used for regeneration, because the label is stuck fast to the record disc and cannot be removed. The destroyed or labeled part is thicker than the regenerated grooved part, and it contains a large quantity of vinyl material. Accordingly, rate of regeneration of material is lower than it could be, due to the destruction of the labeled part.

In making a tape cartridge casing or a tape cassette casing which has a label attached thereto, there is a similar operation of attaching the label to the casing, with resulting disadvantages, as described above.

It is, therefore, a general object of this invention to eliminate the aforementioned disadvantages, to-provide a novel and useful synthetic resin moulded product which has eliminated the necessity of attaching a separate label thereto, and to provide a method of manufacturing the same.

Another object of the invention is to provide a synthetic resin moulded product in which the portion of the product which is equivalent to the label (hereinafter referred to as a label equivalent portion) is moulded integrally with the product proper during the moulding process.

A further object of the invention is to provide a synthetic resin moulded product in which a predetermined pattern made by a combination of lustrous parts and lusterless parts. These parts are formed integrally on the surface of the product during the process of moulding the product. The employment of this predetermined pattern, as the label equivalent portion, has obviated the necessity of using labels-of printed paper or plastic sheet.

A still further object of the invention is to provide a synthetic resin moulded product which is capable of indicating its contents without requiring the attaching of a label to the product, and a method of'manufacturing the same. I

According to an aspect of the invention, this moulded product and the method of manufacturing the same, comprise (2) an elimination of the operation of mounting the labels on the press machine and, therefore, the moulded product is made with less man power and a shortening of the manufacturing cycle. (2) Printing, drying and delivery of the labels are not required, and the cost of the moulded product is reduced by the unit cost of the labels. While the label equivalent portion is formed on a moulding die, and there is a cost for making the forming the label equivalent portion on the die, this initial cost does not really affect the unit cost of the moulded product, because it is distributed over a great number of the products which are moulded by the same die. (3) Irregularity, breakage, or error in mounting of the labels, which often takes place in the conventional products, does not occur. This contributes to an improvement of the good product ratio of the moulded product. (4) The label equivalent portion is made of the same material as the synthetic resin moulded product proper. Accordingly, defectively moulded products are collected and regenerated, and the entire moulded product can be regenerated, as new synthetic resin material and, therefore, the recovery rate of regeneration of material is remarkably improved.

Other objects and features of the invention will become apparent from the description made hereinbelow with reference to the accompanying drawings, in which:

FIG. I is a vertical cross-sectional view of an electroformed plate, formed on a base plate in a process of one embodiment of the method of manufacturing the synthetic resin moulded product embodying this invention;

FIG. 2 is a vertical sectional view of the electroformed plate on which a.predetermined pattern, for a label equivalent portion,is exposed and developed;

FIGS. 3 and 4 are respectively vertical sectional views of the electroformed plate of FIG. 2, respectively showing a state after an etching is made and a state after the photo-resist is removed;

' FIG. 5 is a vertical, partly cross-sectional view of one embodiment of a die press machine for making the label equivalent portion, a part thereof of the label stamping die being cut away;

FIG. 6 is a vertical sectional view of a lacquer master on which a pattern is being pressed;

FIG. 7 is a vertical cross-sectional view of the lacquer master after the pattern has been pressed thereon;

FIGS. 8, 9 and 10 are vertical cross-sectional views respectively of a metal master, a mother and a stamper obtained in sequence from the lacquer master;

FIG. 11 is a vertical cross-sectional view of a label equivalent portion of a record disc, which has been press moulded by stampers shown in FIG. 10;

FIGS. 12 and 13 are respectively vertical crosssectional views of a lacquer master and a metal master showing a process of another embodiment of the method of manufacturing the synthetic resin the moulded product embodying the invention;

FIG. 14 is a vertical cross-sectional view of a mother which as been obtained from the metal master shown in FIG. 13 by preplating the electroforming;

FIGS. 15 and 16 are respectively vertical crosssectional views of the mother before and after the predetermined pattern for a label equivalent portion is exposed and developed;

FIGS. 17 and 18 are respectively vertical crosssectional views of the mother shown in FIGS. 16 after an etching is made thereon and its photo-resist is removed;

FIG. 19 is a vertical cross-sectional view ofa stamper or die obtained from the mother shown in FIG. 18; and

FIG. 20 is a vertical cross-sectional view of a record disc moulded by the stampers or dies.

Each embodiment of the invention will now be described with reference to a method of manufacturing a synthetic resin moulded product here described as a record disc, by way of an example.

First, as illustrated in FIG. 1, a metal plate 10, having a perfect mirror surface, is made a base plate. An oxidized film 11 is formed on this mirror surface by a chromic acid treatment or an electrolytic treatment. Next very fine crystal grains are deposited by electroforming on the oxidized, film 11 of the mirror surface plate 10, whereby an electroformed plate 12 is formed. The electroformed plate 12 is made by, for example, sulfamate acid nickel electroplating with a low current density of less than 5A/cm If a non-conductive plate is used as the mirror surface plate 10, a non-electrolytic plated layer such as a silver mirror or a coppermirror is formed instead of the oxidized film 11.

The electroformed plate 12 is separated from the oxidized film 11, and photo-resist is coated over the separated mirror surface. The photo-resist is exposed to light by using a pattern of letters or figures which are the same as have been used on a conventional label made of printed paper. After the photo-resist is exposed to light, it is developed, and the photo-resist 14 remains on the exposed parts of the electroformed plate 12. In the pattern part 13, other than the parts of the remaining photo-resist 14, the surface of the electroformed plate 12 is exposed.

The electroformed plate 12, having the photo-resist 14 except on the printed pattern part 13, is soaked in an etching solution such as a ferric chroride solution or a mixed solution of nitric acid and acetic acid for effecting etching. Alternatively, the aforementioned etching solution may be sprayed over the electroformed plate 12. Since the pattern part 13 is not covered with the photo-resist 14, the pattern part 13 is corroded by the etching solution The very fine crystal grains of the electroforming are melted away. Consequently, depressions 15a are formed at places which correspond to the pattern part 13, as shown in FIG. 3. The bottom surfaces of the depressions 15a are formed in coarse surfaces 15 having extremely fine projections and depressions exposing crystal surfaces. Then, the photo-resist 14 is removed. As shown in FIG. 4, an electroformed plate 17 has smooth surface 16 at places corresponding to the remaining photo-resist 14. The coarse surface 15 is obtained at depressed places corresponding to the pattern part 13. The smooth surfaces 16 of the electroformed plate 17 have a mirror-like luster, whereas the coarse surfaces 15 having the very fine projections and depressions make satin-like surfaces and appear lusterless and whitish due to diffused irregular reflection of light.

In this embodiment, the depth of the extremely minute projection and depressions is about 3p. and the width about 10p The height of the step between the smooth surface part and coarse surface part is about 3040p.. The above described depth is preferably in a range of l5p., and the width in a range of 5l5;1,. The above described height is preferably in a range of l0l00p..

Nextly, the coarse surfaces 15 of the depressions 15a and the smooth surfaces 16 of the electroformed plate 17 are transferred by electroforming to obtain a die 20. As shown in FIG. 5, it consists of a coarse surfaces 18 having extremely fine, minute projections and depressions on boss parts, and a smooth surface on the depressed parts 19. The die 20 is secured to the lower surface of a support plate 26 of a die press head 21, by means of fasteners 22 and 23. A heater 24 and a cooling pipe 25 are contained in the die press head 21. The die press head 21 is mounted on a lifting and lowering mechanism part 29, which is operated by hydraulic or screw means. The lifting and lowering mechanism part 29 is mounted on a pillar 28 which is fixed to a die press base 27.

A lacquer master 31, on which the recorded sound grooves have been previously cut, is placed on the die press base 27, indexed by a guide pin 30. The lifting and lowering mechanism part 29 is operated to lower the die press head 21. The die 20 is pressed against the lacquer master 31 with a predetermined pressure. The die 20 is heated and cooled while it is so pressing the lacquer master 31. Thus, the pattern of the die 20 is transferred to the surface of the central portion of the lacquer master 31, as shown in FIG. 6.

The die press head 21 is lifted, and the die 20 is removed from the lacquer master 31. A lacquer master 34, having a pattern which is opposite to the pattern of the die 20, as shown in FIG. 7, is obtained. On the surface of'the lacquer disc 34, there is formed a label equivalent portion 35 which consists of coarse suface part 32, having extremely fine, minute projections and depressions. Part. 32 is on the bottom surfaces of the depressed label portions. A smooth surface appears at part 33. I

In the present embodiment, the pressing by the die 20 is made on the lacquer master 31 on which sound grooves are previously formed by a cutting stylus. It is to be noted, however, that the pressing by the die 20 may also be made on a lacquer disc before the cutting of the sound grooves.

By using the lacquer master 34, having the label equivalent portion 35 formed beside the sound grooves 36, a metal master 37 (FIG. 8) is made by transfer of both the label equivalent portion 35 and the sound grooves. Then, a mother 39 (FIG. 9), having a label equivalent portion 40 and sound grooves, is formed from the metal master 37. A stamper 41, as shown in FIG. 10, having a label equivalent'portion 42, is obtained from the mother 39. The label equivalent portion 42 of the stamper 41 has, as in the die 20, a coarse surface part having extremely fine, minute projections and depressions on the projected surface and a smooth surface part on the depressed surface. The process by which the lacquer master 34, metal master 37, mother 39, and the stamper 41 are obtained in sequence is so well known that a detailed description thereof will be omitted.

Both the A-side stamper and B-side stamper are formed by the above described process. These A-side and B-side stampers are then mounted on a press machine which may be of any conventional type. A re quired quantity of synthetic resin material which has been preheated and kneaded is injected between the two stampers and press moulded to obtain a record disc 43 as shown in FIG. 11.

Label equivalent portions 44a and 44b of the record disc 43 consist of coarse surface parts 45a and 45b having extremely fine projections and depressions on the depressed bottom surface and smooth mirror-like surface parts 46a and 46b projected above the coarse surface parts. The coarse surfaces parts 450 and 45b appear lusterless and whitish due to an irregular reflection of light. The smooth surface parts 46a and 46b, which have a mirror-like luster, appear lustrous when they reflect light, and their ground color itself appears when they do not reflect light. Accordingly, the pattern of letters and figures formed of the smooth surface parts 46a and 46b stand out in relief on the lusterless and satin-like coarse background surface parts. Thus, the contents of a label are shown on the label equivalent portion formed in the above described manner, without using a conventional printed label.

In the present embodiment, parts corresponding to letters and figures are formed as the upstanding smooth surfaces, and the background is the rest of the parts, which background is the coarse surfaces on the moulded record disc. However, this construction may be reversed. Namely, the parts corresponding to letters and figures may be formed as the coarse surfaces and the rest of parts as the smooth surfaces. In this case, a pattern which is opposite in positive and negative to the one shown in FIG. 2 is used when the photo-resist is exposed to light.

Next, to be described is a second embodiment of the method of manufacturing the synthetic resin moulded product embodying the invention, with reference to FIG. 12 through FIG. 20.

Flrst, as shown in FIG. I2, a lacquer master 50 having sound grooves 51 is prepared by a stylus cutting on a lacquer disc. A silver'mirror treatment, incorporating nickel preplating and electroforming, is deposited on the lacquer master 50, in a well known manner. Then, the silver mirror is separated from the lacquer master 5 0 to obtain a metal master 52 shown in FIG. 13.

The surface of the metal master 52 is rinsed. Then, after a separation treatment is effected on this surface, preplating and electroforming are made. These are separated, at the separation treated surface, from the metal master 52.to obtain a mother 53 shown in FIG. 14. The mother 53 includes a preplated layer 54 and an electroformed plate 55. The preplated layer 54 of the mother 53 has a smooth surface.

Next, as shown in FIG. 15, an acid-proof lacquer mask 57 is applied to the surface of the mother 53, except on its label equivalent portion 56 near the center thereof. After the masking, photo-resist is coated on the label equivalent portion 56 of the mother 53. The

photo-resist is exposed to light, by using a pattern of letters and figures,'and then it is developed. The photoresist 59 remains in the places other than the pattern parts 58, as shown in FIG. 16. In the pattern parts 58, the surface of the preplated layer 54 of the mother 53 is exposed.

The mother 53 having the photo-resist 59 and the acid-proof lacquer 57 is soaked in an etching solution, such as a ferric chroride solution or a mixed solution of nitric acid and acetic acid for etching. The pattern parts 58 of the mother 53 is eroded by the etching solution, and very fine crystal grains of the preplated layer 54 melt away. As a result, depressions 60a are formed at places corresponding tothe pattern parts 58. The coarse on the bottom surfaces of the depressions 60a have extremely fine minute depressions and projections. During the etching step described above, the duration of the etching bath and the type of solution used for etching are selected so that the depth D of the etching made in the depressions 60a is less than ,the thickness D 1 of the preplated layer 54, namely, a relationship of D D should be satisfied.

Then, the photo-resist 59 and the acid-proof lacquer 57 are removed, and the mother 53 is rinsed. After etching (FIG. 18), a mother has been produced which has smooth surfaces 61 at places corresponding to the remaining photo-resist 59. The coarse surfaces 60 are produced at depressed places corresponding to the pattern parts 58. The smooth surfaces 61 of this mother 62 have a mirror-like luster. The coarse surfaces 60 appear lusterless and whitish due to irregular reflection of light.

Next, as shown in FIG. 19, a separating film 63 is deposited on the surface of the mother 62, and after which preplating and elec'troforming are effected. A preplated layer 64 and an electroformed plate 65 are separated, by the separating film 63, from the mother 62 to obtain a stamper 66. The stamper 66 is formed on the upper surface thereof with a label equivalent portion 69 which consists of coarse surface parts 67 having extremely fine minute projections and depressions. A smooth surface appears at parts 68.

By the foregoing process, an A-side stamper and a B- side stamper are formed. As shown in FIG. 20, the A- side stamper 66a and the B-side stamper 66b are mounted on a press machine, which may be of any conventional type. A required quantity of synthetic resin material, which has been preheated and kneaded, is injected between the two stampers 66a and 66b and press-moulded. Thus, a record disc 70, made of the synthetic resin material 71, is obtained. On both sides of the record disc 70, label equivalent portions 74a and 74b are formed corresponding to the label equivalent portions 690 and 69b of the stampers 66a and 66b. The label equivalent portions 740 and 74b include coarse surface parts 72a and 72b and smooth surface parts 73a and 73b, which respectively correspond to the coarse surface parts 67a and 67b and the smooth surface parts 68a and 68b of the label equivalent portions 699a and 69 b of the stampers 66a and 66b.

The coarse surface parts 72a and 72b of the record disc 70 appear lusterless and whitish due to irregular reflection of light. The smooth surface parts 73a and 73b have a mirror-like luster. Accordingly, as in the record disc made according to the method of the first embodiment described above, the pattern of letters and figures composed of the smooth surface parts 73a and 73b stand out in relief on the lusterless and satin-like coarse surface parts 72a and 72b.

in this embodiment also, the parts corresponding to letters and figures may be formed as the lusterless coarse surface and the rest is a smooth lustrous surface. In this alternative case, the opposite pattern, to the one shown in FIG. 16, is used when the photo-resist is exposed to light.

In this embodiment, the etching treatment for forming the coarse surfaces is performed on the mother. However, the etching treatment for forming the coarse surfaces may also be performed on the metal master or stamper.

In each embodiment described above, the coarse'surfaces are formed on the bottom surfaces of the depressed parts, and the smooth surfaces are formed on the upper surfaces of the projecting parts. Conversely, the coarse surfaces maybe formed on the upper surfaces of the projecting parts, and the smooth surfaces are formed on the bottom surfaces of the depressed parts.

Again, each of the foregoing embodiment has been explained with reference to a record disc, which was taken by wayof an example of the synthetic resin moulded product. This record disc, invention, however, is not limited to this but is applicable to a tape cartridge casing, a tape cassette casing, and any other synthetic resin moulded products which have heretofore required a separate operation of attaching a label thereto. v

This invention is not limited to these embodiments but various modifications may be made without departing from the scope and spirit of the invention.

What 1 claim is: v l. A synthetic resin moulded phonograph record disc comprising a label equivalent portion formed by moulding a portion of the surface of said moulded phonograph record disc, with said label equivalent portion formed in a part other than the sound grooves of said phonograph record disc comprising a surface part in which a predetermined pattern is formed by a combination of smooth surfaces having a mirror-like light reflecting characteristic and uniformly coarse surfaces, said coarse surfaces having projections and depressions, the depth of the projections and depressions being in a range of 1-5 p. and the width thereof in a range of 5-l5 u, and irregular light reflection surfaces on said coarse surface parts to form a lusterless part contrasting with the luster of said smooth mirror reflection surface parts, whereby said label equivalent portion indicates a predetermined pattern by a contrast between the lusterless coarse surface parts and the lustrous smooth surface parts.

2. The synthetic resin moulded phonograph record disc ofclaim 1 wherein letters, figures or other designations are formed in said predetermined pattern by said smooth surface parts with a background of said coarse surface parts.

3. The synthetic resin moulded phonograph record disc of claim 1 wherein letters, figures or other designations are formed in said predetermined pattern by said coarse surface parts with a background of said smooth surface parts.

4. The synthetic resin moulded phonograph record disc of claim 1 wherein said label equivalent portion further comprises depressed portions each having a coarse surface on the bottom thereof, the height between the depressed portion and said smooth surface being in a range of lO-lOO p.. 

1. A synthetic resin moulded phonograph record disC comprising a label equivalent portion formed by moulding a portion of the surface of said moulded phonograph record disc, with said label equivalent portion formed in a part other than the sound grooves of said phonograph record disc comprising a surface part in which a predetermined pattern is formed by a combination of smooth surfaces having a mirror-like light reflecting characteristic and uniformly coarse surfaces, said coarse surfaces having projections and depressions, the depth of the projections and depressions being in a range of 1-5 Mu and the width thereof in a range of 5-15 Mu , and irregular light reflection surfaces on said coarse surface parts to form a lusterless part contrasting with the luster of said smooth mirror reflection surface parts, whereby said label equivalent portion indicates a predetermined pattern by a contrast between the lusterless coarse surface parts and the lustrous smooth surface parts.
 2. The synthetic resin moulded phonograph record disc of claim 1 wherein letters, figures or other designations are formed in said predetermined pattern by said smooth surface parts with a background of said coarse surface parts.
 3. The synthetic resin moulded phonograph record disc of claim 1 wherein letters, figures or other designations are formed in said predetermined pattern by said coarse surface parts with a background of said smooth surface parts.
 4. The synthetic resin moulded phonograph record disc of claim 1 wherein said label equivalent portion further comprises depressed portions each having a coarse surface on the bottom thereof, the height between the depressed portion and said smooth surface being in a range of 10-100 Mu . 